Press unloader including magnetic lift means and magnetic delivery rollers



March 28, 1961 A. FOWLER ETAL 2,976,753

PRESS UNLOADER INCLUDING MAGNETIC LIFT MEANS AND MAGNETIC DELIVERY ROLLERS Filed June 5, 1956 2 Sheets-Sheet 1 INVENTORS ALEXANDER FOWLER VELYN R. FOWLER March'28, 1961 A. FOWLER E'AL 2,976,753

PRESS UNLOADER INCLUDING MAGNETIC LIFT MEANS AND MAGNETIC DELIVERY ROLLERS Filed June 5, 1956 FIGS ALEXANDER FOWLER Y EVELYN R. FOWLER United States Patent 6 PRESS UNLOADER INCLUDING MAGNETIC MEANS AND MAGNETIC DELIVERY ROLLERS Alexander Fowler and Evelyn R. Fowler, both of 334 Westover Road, Stamford, Conn.

Filed June 5, 1956, Ser. No. 589,456

6 Claims. 01. 83-82 This invention relates to power presses working on ferrous metal, and more particularly to auxiliary apparatus for unloading from the press the material already worked on.

. The primary object of the present invention is to generally improve power press'operation, and more particularly to improve the operation of unloading or clearing the.

press after each cycle of operation, preparatory to the next. A more specific object is to provide apparatus which operates automatically, in properly timed relation to the their relation one to another and to the punch press, as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings in which:

Fig. 1 is a side elevation of a typical punch press with which the present invention may be employed;

Fig. 2 is a partially sectioned front elevation of the die and unloading apparatus;

Fig. 3 is a plan View of a part of the unloading apparatus;

Fig. 4 is a front elevation similar to Fig. 2, but showing a modification in which the scrap instead of the work is unloaded;

Fig. 5 is a partially sectioned front elevation similar to Fig. 2, but showing a modification in which the roller track is carried by the press ram;

Fig. 6 is a front elevation similar to Fig. 2, but showing a modification in which the roller track oscillates and acts also as a lift magnet;

Fig. 7 is a front elevation which combines some of the features of Figs. 2 and 6; and

Fig. 8 is a schematic wiring diagram explanatory of I the electrical circuit of the apparatus.

Referring to the drawing, and more particularly to Fig. l, we there show a typical power driven press having a rigid 0. frame 12 carrying a bed 14 and having upright ways to reciprocally guide a ram 24 reciprocated by a suitable eccentric on a main shaft 18 carrying a weighty flywheel 20. The main shaft is driven by a motor through suitable reduction gearing and a singlerevolution clutch. The press further comprises a suitable release mechanism for engaging the clutch and causing the press to turn through one revolution or cycle, whereupon it is again stopped. The release means may be a foot treadle, or

hand lever, or in many instances spaced-apart left and right buttons both of which must be pressed, thereby insuring that the hands of the operator have been removed .from the press before it is operated. These things are all conventional.

Referring now to Fig. 2 of the drawing, the stationary bed carries a stationary bottom die' 22,v While the re- "cipro'cabl'eram 24 carries a 'movable'topdie26. The

press and die operate on a blank of ferrous metal in sheet form, indicated at 28, and this blank may be positioned by suitable steps or locating means 30. In the particular case here shown the top die 26 functions primarily as a punch holder, and carries a number of punches for operating on the blank 28. Two such punches are indicated at 32, and the scrap metal excised by these punches moves down through the openings 34 in bottom die'22, and eventually falls gravitationally through the bed of the press into a suitable scrap box. The blank 28 tends to stay with the punches 32, and the top die 26 is accordingly provided with a resiliently actuated stripper plate 36, urged downward by compression springs 38.

In accordance with one aspect of the present invention, the press is provided with a track of magnetic feed rollers 40, and these are driven by a motor 41 which rotates the feed rollers in proper direction to feed the metal blank out of the press, as indicated in broken lines at 28. In accordance with another aspect of the invention the top die the action of the stripper plate 36 would be to leave the ,ried by a pin 44 and may, if desired, be additionally guided by a guide 46. The magnet may fall gravitationally as the ram rises, or, if desired, a spring 48 may be provided. It will be understood from inspection of the drawingthat the magnet descends far enough to clear the blank from the stripper 36, which in turn clears the blank from the punches 32, so that the latter will not prevent sideward movement of the blank.

In addition to the foregoing, the-auxiliary apparatus comprises a horizontally movable pusher 50 which, in the present case, is carried by the die 26, as by means of a suitable guide bracket 52. The pusher is disposed at proper height to engage the edge of the blank when the ram rises. The pusher then serves to slide the blank sideward until the right edge of the blank reaches the magnetic roller track 40. The pusher 50 may be operated in any desired fashion, for example, pneumatically, electrically, or hydraulically, but in the present case is operated mechanically by means of an angle lever 54 pivoted at 56, and operated by a generally upright link 58. The connection between arm 54 and pusher 50 includes a short horizontal link 55 for angularity (or an uprightslotted connection could be used). The upper end of the link is stationarily mounted at 60, and thus the pusher is operated as the ram rises. v I v The magnet 42 is an electro magnet, and may be conventional in construction. In the present case a coil 62 is received in an annular space in a soft iron core 42. When the magnet is in contact with the blank 28 the magnetic flux path is completed through the blank 28.

The magnetic rollers 40 may be of conventional construction, and one arrangement is schematically indicated in Fig. 3, in which each roller 49 has a series of coils 62.

The coils are energized through suitable slip.ring connections 64 and 66. The rollers are all inter-connected to rotate in unison. This may be done by belts, sprocket chains or the like, but in the present case gearing is used, each roller carrying a gear 68, and these being connected by idlers 70. This has the advantage that the rollers turn in the same direction, as they should, and also the gears 68 and 70 may be smaller ,in diameterthan the rollers.

Motor 41 may be connected to any desired oneo the rollers, as by means of a pulley and belt drive shown at 72 in Fig. 2. It will be understood that the showing'bf "the magnetic rollers'in Fig; 3 is schematic rather than "order not to interfere with the punch operation.

structural. The rollers are shown to be electro magnetic,

and in such case the rollers may be energized intermittently, first, to conserve power, and, second, to facilitate dropping the blank when it has been rolled out of the press. However, the rollers may be energized continuously, in which case the blank may be dropped gravitationally when it reaches the last roller, which roller may be designed to have insuflicient magnetic attraction to itself hold the blank. With continuous magnetization it also is possible to employ permanent magnet rollers, instead of electro magnetic rollers as here shown.

The wiring for the press unloader apparatus is shown in Fig. 8 of the drawing. Power is supplied through the lines L1 and L2. The lift magnet is indicated at 42, and the magnetic rollers at 40. The latter may be connected across the line by means of the contact 74 of a time delay relay 76. The lift magnet 42 may be connected across the line by means of the contact 78 of a time delay relay 80. The motor 41 which drives the rollers is connected directly across the line, and runs continuously when the main switch 82 is closed. A conventional fuse or circuit breaker is provided at 84.

The time delay relays are energized by means of a contact 86 operated by a cam 88 driven by the main shaft of the press. Reverting to Fig. 1, the contact is housed at '86 and is driven by the main shaft 18. This establishes a desired time relationship, and in the present case both relays are closed at the same time, although relay 76 for the rollers could be closed somewhat later. The relay time delay is differently adjusted for the relays, the lift magnet 42 being tie-energized when the ram rises and the blank has been taken over by the roller track. The latter remains energized long enough to deliver the blank from the press a desired distance, at which point the blanks may be dropped.

The roller magnets40 may be shunted by a condenser 90, and the lift magnet 42 may be shunted by a condenser 92, for obvious reasons of power factor correction, reduction of arcing at relay contacts 74 and 78, etc. Also it produces a decaying oscillatory discharge through the coil, which has a de-magnetizing eifect on the work.

Referring now to Fig. 4, we there show a modification in which the unloading apparatus is used to unload the scrap rather than the blank. The blank 100 has a very large hole punched therethrough by means of a punch 102, to make, for example, a window fan bafile. The scrap is itself a relatively large piece of metal 104. In

the present arrangement the blank 100 is located on bot-.

tom die 106 by stops 108. The bottom die is provided with strippers or ejectors 110 to force the scrap 104 up out of the bottom die. The top die 112 carries a stripper plate 114 operated by springs 116 to strip the blank 100 from the punch 102, letting it remain on the bottom die as the punch rises.

In addition, the top die 112 carries a lift magnet 118, which may yield upwardly, as previously described, in The magnet later may fall gravitationally or may be aided by a compression spring 120. The magnet then supports the scrap 104 at a height somewhat lower than that of the stripper plate 114. This exposes its edge to the action of a horizontally movable pusher 122, which again may be operated in any desired fashion, as by a piston and cylinder, or by linkage described in connection with Figs. 1 and 2. The pusher moves the scrap over to attack of magnetic rollers indicated at 124, and these are driven by .a motor 126. It will be understood that the wiring or control circuit for the parts shown in Fig. 4 may be the same as that already described in connection with the Fig. 8 of the drawing.

Fig. shows another modified form of the invention. One difference is that the work is being formed or drawn or bent. track'and its driving motor are carried by the press ram 24. The bottom die 130 carries a part 132 around which .a

Another difference is that the magnetic roller Y 4 blank 134 is pushed or drawn, as shown at 136. There are resilient strippers 138 to help free the formed blank from the bottom die 132. The latter also has stops 140 to initially locate the blank 134.

The top die 142 is carried by ram 24. The working part of the die is indicated at 144, and in the present case engages the ends of the blank and draws them downward around the lower die 132. The top die has lift magnets 146 which'are upwardly movable in order not to interfere with the forming operation. They'move downward gravitationally, and if desired, may be aided by compression springs 148. In downward position the blank is below the die portion 144, and is free to be moved sideward, as by means of the pusher 150. This again may be operated by a piston and cylinder mechanism, or by linkage such as that shown in Fig. 2. The pusher is retracted during the forming operation, and is effective only when the ram rises. It operates to push the blank sideward to a track of magnetic rollers 152 driven by a motor 154 through a belt drive 156. The rollers are suitably inter-connected to rotate in unison, as by means of gear ting described in connection with Fig. 3. It will be noted that the roller track and its motor are carried on a frame "158, which is mounted on the ram 24 and reciprocates with it.

We consider such an arrangement 'less preferable than a roller track which is stationarily mounted at desired elevation, as previously described in connection with Figs. 2 and 4, because ordinarily it is undesirable to reciprocate a large mass when there is no need for it. However, Fig. 5 illustrates the possibility. The electrical circuit for the apparatus shown in Fig. 5 may be the same as that already described in connection with Fig. 8.

Still another form of our invention is illustrated in Fig. 6. In this case no separate lift magnet is employed. Instead the first of the roller track magnets may itself function as a lift magnet. Specifically, the bottom die is generally like that shown in Fig. 2, and receives a blank 162 located by stops 164. The blank is operated on by punches 166 carried by a punch holder or top die 168,

which in turn is mounted on the ram 24. The top die includes a stripper plate 170, which is yieldable upward against compression springs 172.

In this case the initial blank 162 is larger in area than that shown in Fig. 2, and there is an outward area exposed for engagement by the end roller 174 of a roller track 176. The latter is stationarily pivoted at its outer end 178, while its inner end is supported by a link connected at 182 to the ram 24. There is preferably a lost motion slot at 184.

It will be evident that with this arrangement the inner end of the roller track rises and falls with the ram, and when the ram is in down position the roller track engages the blank 162. When the ram rises the roller track lifts the right end of blank 162 so that it can move over the stop 164, whereupon the rotation of the rollers moves the blank sidewardly along the bottom of the roller track, much as previously described. The rollers may be geared togetherand driven by a motor 186, substantially as previously described. The pulley drive 188 extends to a lower pulley which is coaxial with the pivot 178 about which the roller track oscillates, for in that case there is no lengthening or shortening of the belt. The arrangement of Fig. 6 dispenses not only with the lift magnet, but also with the pusher mechanism.

The electrical circuit for the apparatus shown in Fig. 6 is the same as the lower half of what is shown in Fig. 8. On examination of Fig. 8 it will be seen that one may omit the lift magnet 42 and its relay 80 without disturbing the lower half of the circuit including the cam operated contact 86, the relay 76, the roller magnet 41), and the motor 41. These parts are all retained and used for the apparatus shown in Fig. 6, while eliminating the lift magnet 42 and its relayr80.

The pusher mechanism may be eliminated whenever arrangement is shown in Fig. 7 of the drawing, which generally resembles Fig. 2 in that ram 24 carries a top die 26 having a shipper plate 36 and a lift magnet 42, all as previously described in connection with Fig. 2. However, the bottom die 190 is larger in area, and stops 192 are spaced apart to receive a blank 194 which extends outward from the top die 26. Thus one (or more) roller 196 of roller track 198 is disposed over the right end of blank 194, but the roller 196 is cleared by the top die 26 and ram 24 during the operation of the press. Roller track 198 is driven by motor 200, and both are mounted on a stationary frame 202.

The punches carried by the top die perforate the blank 194 to produce the desired holes. As the ram rises the blank is stripped from the punches by the stripper plate 36, but the magnet 42 holds the blank, and the latter rises with the magnet, as shown at 194'. As the ram rises the blank engages the roller (or rollers) 196, and preferably at about this time the lift magnet 42 is deenergized, whereupon the blank is fed outward by the roller track.

The electrical circuit for the apparatus shown in Fig. 7 may be identical with that shownin Fig. 8.

It is believed that the construction and operation of our improved press unloader, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will also be understood that the various features shown are illustrative, and may be combined in different 'ways. For example, the stationary roller tracks shown in Figs. 2 and 4 may be used when drawing instead of punching a blank, as shown in Fig. 5, and, conversely, the ram carried roller track of Fig. 5 may be used when punching a blank instead of drawing a blank. A roller track which acts also as a lift magnet, as shown in Fig. 6, may be used while reciprocating the entire roller track, as shown in Fig. 5, instead of one end only, as shown in Fig. 6. A pusher may be eliminated whenever the blank has an adequate overhang, whether the roller track be fully reciprocable, as shown in Fig. 5, or oscillated, as shown in Fig. 6, or stationary, as shown in Fig. 7.

In the drawings we show conventional strippers, and lift magnets in addition. When the lift magnets are spring pressed they may themselves be used as strippers, and the latter eliminated. This applies to Figs. 2, 4, 5 and 7. Viewed, differently, the strippers may be magnetized, in order to hold, as well as strip.

It will therefore be apparent that while we have shown and described our invention in several preferred forms, changes may be made in the structures shown, without departing from the scope of the invention as sought to be defined in the following claims.

We claim:

1. In a metal fabricating system in which a punch press has a stationary bed carrying a stationary bottom die and has a vertically reciprocable ram carrying a movable top die, and in which the press and die operate on ferrous metal, the combination with the said press and die, of a magnetic feed roller located laterally of and close to the top die in its upper position, and means including electromagnetic means associated with the top die to lift said ferrous material with the top die so that a. portion of said ferrous metal substantially engages said magnetic feed roller, means to de-energize said electromagnetic means when a portion of said ferrous metal substantially engages said magnetic feed roller, and a motor for rotating said feed roller in order to feed the ferrous material laterally out of the press and die.

2. In a metal fabricating system in which a punch press has a stationary bed carrying a stationary bottom die and has a vertically reciprocable ram carrying a movable top die, and in which the press and die operate on ferrous material, the combination with the said press and die, of a magnetic means associated with the top die to lift ferrous material with the top die, a magnetic feed roller located laterally of and immediately adjacent the top die in its upper position, said rollerbeing exposed at the bottom in order to receive and support the said ferrous material beneath the roller, and a motor for rotating said feed roller in proper direction to feed the ferrous material laterally out of the press and die.

3. In a metal fabricating system in which a punch press has a stationary bed carrying a stationary bottom die and has a reciprocable ram carrying a movable top die, and in which the press and die operate on ferrous material in sheet form, the combination with the said press and die, of a magnetic means associated with the top die to lift ferrous sheet material with the top die, a track of magnetic feed rollers located side by side laterally of the top die with the first roller immediately adjacent the top die in its upper position, said rollers being exposed at the bottom in order to receive and support the said ferrous material beneath the track of rollers, and a motor for rotating said feed rollers in proper direction to feed the ferrous sheet material laterally out of the press and die.

4. In a metal fabricating system in which a punch press has a stationary bed carrying a stationary bottom die and has a reciprocable ram carrying a movable top die, and in which the press and die operate on ferrous material, the combination with said press and die, of a lift magnet carried by the top die for holding the material near the top die, said lift magnet being vertically yieldable when the die is closed in order to avoid interference with the die operation, a track of magnetic feed rollers disposed side by side at one side of the top die with the [first roller immediately adjacent the top die in its upper position, said rollers being exposed at the bottom in order to receive and support the ferrous material beneath the track of rollers, and a motor for rotating said rollers in proper direction to feed the ferrous material laterally out of the die.

5. In a metal fabricating system in which a punch' press has a stationary bed carrying a stationary bottom die and has a reciprocable ram carrying a movable top die, and in which the press and die operate on ferrous material, the combination with said press and die, of a lift magnet carried by the top die for holding the material near the top die, said lift magnet being vertically yieldable when the die is closed in order to avoid interference with the die operation, a track of magnetic feed rollers disposed side by side at one side of the top the with the first roller immediately adjacent the top die in its upper position, said rollers being exposed at the bottom in order to receive and support the ferrous material beneath the track of rollers, switch means automatically operated by said punch press to deenergize said lift magnet when said rollers receive said ferrous material, and a motor for rotating said rollers in proper di rection to feed the ferrous material laterally out of the die.

6. In a metal fabricating system in which a punch press has a stationary bed carrying a stationary bottom die and has a reciprocable ram carrying a movable top die, and in which the press and die operate on ferrous material in sheet form, the combination with said press and die, of a lift magnet carried by the top die for holding the material near the top die, said lift magnet being vertically yieldable when the die is closed in order to avoid interference with the die operation, a track of magnetic feed rollers disposed side by side at one side of the top die with the first roller immediately adjacent the top die in its upper position, said rollers being exposed at the bottom in order to receive and support the ferrous material beneath the track of rollers, a motor for rotating said rollers in proper direction to feed the ferrous sheet material laterally out of the die, a horizqntally movable pusher, and meanscontrolled by the press tq move said pusher against the sheet material when ythe a-m rises' inflprder to move the sheet materialzs'idewardly to the bgttom of said track of feed rollers.

References Cited in the file of this patent UNITED STATES PATENTS gauges 8 H1;ston Apr. 10, 1928 Tobeler Sept. 4, 192,8 Altv ate r Mar. 14, 193.3 r-'-- -:---r.-:-- Bridges, V July 14, 1942 Haegele et al-. MaI.-30, 1943 Wales July 20, 1943 OLB IY -4- May29, 19 45 Burgess Apr. 18, 1 950 'Buceicone Oct. 13, 1953 

